A cutting tool (a surface-coated tool) of which various characteristics represented by wear resistance have been improved by forming a coating film on a surface of a substrate has been known [see, for example, Japanese Patent Laying-Open No. 7-310174 (PTD 1), International Publication WO2006/070730 (PTD 2), Japanese Patent Laying-Open No. 8-127862 (PTD 3), and Japanese Patent Laying-Open No. 2007-31779 (PTD 4)].